The present invention relates generally to surgical retractors, and more particularly to adjustable surgical retractors for use in expanding incisions performed during surgery.
Abdominal retractors are well known, and are typically used during surgery to expand incisions so that body parts under the incision may be accessed by the surgeon. One well-known type of abdominal retractor is a metal retractor. Metal retractors are typically placed at opposite sides of the incision to expand the incision for surgery. Metal retractors have often been used with cotton sponges held against the sides of the incision by the retractors.
Other types of retractors include wound edge protectors. Examples of wound edge protectors include those shown in U.S. Pat. Nos. 3,347,226 and 3,347,227. However, these wound edge protectors do not adjust the vertical length of the sleeve. Wound edge protectors typically have an inner ring spaced from an outer ring with a flexible sheet of material formed into a sleeve extending between the rings and connected at opposite ends to the rings. During surgery, the inner ring is squeezed into an oblong shape to be inserted through the wound and to be allowed to expand against the inside edge of the wound. The outer ring overlaps the outside edge of the wound to cause the sleeve to contact the sides of the wound and expand the wound for surgery. The sides of the wound are also protected by the sleeve from contamination during surgery. These wound edge protectors are typically not adjustable and numerous different sized retractors are required having varying sized rings and/or sleeve lengths for different sized wounds.
In another known wound edge protector, the circumference of the wound edge protector is adjustable by use of telescoping inner and outer rings and overlapping lengthwise sleeve edges.
Also known is an incision liner and retractor which is similar in construction to wound edge protectors. In the incision liner and retractor, the length of the sleeve is incrementally adjustable by rolling the sleeve onto the circumference of the outer ring by rotating the outer ring about its central axis. In one example, the outer ring has an oblate cross-section with opposed flat chordal surfaces to assist in rotating the ring about its central axis. However, manually rotating the outer ring about its central axis is often difficult. An example of such an incision liner and retractor is found in U.S. Pat. No. 5,524,644.
In one aspect of the invention, an adjustable retractor is disclosed. The adjustable retractor comprises an inner ring, an outer ring spaced from the inner ring, and an elongate sleeve open at opposite ends. The sleeve extends between the inner and outer rings and is connected at its opposite ends to the inner and outer rings. The outer ring is provided with a pre-loaded rotational torque to assist with rotation of the outer ring about its central axis to roll the sleeve about the outer ring to adjust sleeve length.
According to one embodiment, the outer ring is formed in a mobius configuration to provide the pre-loaded rational torque of the outer ring. In the mobius configuration, an outer circumference is rotationally offset or twisted by a predetermined amount about the central axis of the outer ring along the length of the ring. The outer ring may include a tube having two ends secured together, the circumferences of the ends being offset from one another. The offset may be gradual, proceeding longitudinally along the central axis of the outer ring. In another embodiment, the offset may be discontinuous or occur in at least one step. According to another embodiment, the circumference is offset at least about 20xc2x0 about the central axis of the outer ring. The circumference may be offset between about 45xc2x0 and about 540xc2x0 about the central axis of the outer ring. In another embodiment, the predetermined amount of the offset may be about 180xc2x0 or about 360xc2x0.
In another embodiment, the cross-section may be shaped in numerous different configurations including substantially circular, substantially triangular, substantially star-shaped having at least four points, substantially parallelogram, substantially polygonal, or substantially cruciform.
According to another embodiment, the one location has a cross-sectional shape that matches a cross-sectional shape at the other location. The outer circumference of the outer ring at the one location may be offset with respect to the outer circumference at the other location about the central axis of the outer ring by an amount to match the cross-sectional shape at the one location with the cross-sectional shape at the other location. The outer circumference of the cross-section at the one location may be offset 180xc2x0 about the central axis of the outer ring to with respect to the outer circumference at the other location.
According to another embodiment of the invention, in operation the entire outer ring is rotatable manually about its central axis. The sleeve may be a thin, flexible sheet having overlapping sealed edges to form a cylinder. In yet another embodiment, the sleeve may be seamless. The opposite ends of the sleeve may be wrapped about the rings and secured to the sleeve. The inner ring may be squeezable into an oblong shape for insertion into a surgical incision and may be constructed to return to its original shape when released to bear against an inner edge of a surgical incision. Length of the sleeve may be adjustable to locate the outer ring against an outer edge of a surgical incision. The length of the sleeve may be adjustable before or after insertion of the inner ring into a surgical incision.
In another embodiment of this aspect of the invention, an adjustable retractor comprises an inner ring squeezable into an oblong shape for insertion into a surgical incision and structured to return to its original shape to bear against an inner edge of the surgical incision. An outer ring is spaced from the inner ring, the outer ring being formed in a mobius configuration. A sleeve having two ends extends between the inner and outer rings. The inner and outer rings are secured to the opposite ends of the sleeve. The outer ring in operation is rotatable about its central axis to roll the sleeve about itself and the outer ring and thereby adjust sleeve length to locate the outer ring adjacent an outer edge of the surgical incision.
In one embodiment, the outer ring has a cross-sectional shape, the mobius configuration may include one location on an outer circumference of the outer ring rotationally offset with respect to another location by a predetermined amount about the central axis of the outer ring. The offset may be gradual, proceeding longitudinally along the central axis of the outer ring. In another embodiment, the offset may be discontinuous or occur in at least one step. The outer circumference may be offset at least about 20xc2x0 about the central axis of the outer ring. In another embodiment, the outer circumference may be offset between about 45xc2x0 and about 540xc2x0 about the central axis of the outer ring. The one location may have a cross-sectional shape that matches a cross-sectional shape at the other location. The outer circumference of the outer ring at the one location may be offset with respect to the outer circumference at the other location about the central axis of the outer ring by an amount to match the cross-sectional shape at the one location with the cross-sectional shape at the other location. The outer circumference of the cross-section at the one location may be offset 180xc2x0 about the central axis of the outer ring to with respect to the outer circumference at the other location. The outer ring may have a cross-sectional shape in numerous different configurations.
In yet another aspect of the invention, a method of adjusting a retractor is disclosed. The method comprises the steps of: providing an inner and an outer ring spaced apart from one another, providing an elongate sleeve extending between the inner and outer rings, the sleeve having a length and two opposed ends, each end being secured to one of the inner and outer rings, providing a pre-loaded rotational torque on the outer ring, and adjusting the length of the sleeve by rotating the outer ring about its central axis with the assistance of the pre-loaded torque to roll the sleeve about itself and the outer ring to adjust sleeve length. According to one embodiment, the outer ring is formed in a mobius configuration to provide the pre-loaded rotational torque on the outer ring.